[Edi]

The problem is that there are gaps in the nation number list and not all nations in a given era are consecutive. E.g. Lanka is 68 and in EA, Eriu is 69 and in MA, Serpent Cult Pythium is 70 and in LA.

Consult the DB for an up to date list and how you need to do them. You are probably going to have to put them manually, unless you want to have everything from all eras allied on a SP map. That last one is easy to automatem just skipping 23, 24 and 25 allying with anything.